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Fuel Vent Venting LOTS of Fuel

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Joined
Mar 25, 2013
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This started last year and is gradually getting worse. A small metal line exits the bottom of the fuselage just below and aft of the left pedal. For two years I didn't know what this line did because I never observed anything exiting it. Last year I noticed that fuel would drip slowly for about 30 minutes after parking. The drips were about 1 every 5-10 seconds. Recently the dripping has become more copious. During start and taxi, fuel now exits against the lexan floor and I can watch what appears to be a constant splatter. It continues to vent in flight but not enough to stain the bottom of the fuselage nor make a noticeable change in fuel depletion.

I just had the panels off to install a new oil pressure/temperature gauge and make some changes to the electrical distribution. I really regret not addressing this then. The vent routes up to the top of the tank at a T-fitting. The other end of the fitting connects to the line that serves as the fuel quantity gauge along the right side of the panel. That line hits another T-fitting at the bottom of the tank where a second line stops at a dead end in front of the throttle.

I tried bending the offending metal vent tube line forward thinking that maybe prop- and airflow were creating suction. But that changed nothing. So something is either pressurizing the tank or somehow too much fuel is exiting the left side of that T-fitting at the top of the tank.

Any thoughts? (Besides don't fly :) Thanks.
 

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